Hi gsmith1610, this is a known issue in the 1803 Update,
It is the recovery drive, you are not meant to see it, it is not meant to have a drive letter, remove the drive letter and everything will return to normal:
Click your Start Button, type cmd, then right click Command Prompt and choose 'Run as Administrator'
Run this command and hit Enter
diskpart
In the new Command Window, run this command and hit Enter
select volume E
Run this command and hit Enter
remove letter=E
Close Command Prompt and restart your PC
That's It!